diff --git a/API.md b/API.md
index eba46541..b3320ad9 100644
--- a/API.md
+++ b/API.md
@@ -48349,6 +48349,7 @@ typesToActivate=["Cluster","Project"] this will actiate MongoDB::Atlas::Project
 | <code><a href="#awscdk-resources-mongodbatlas.AdvancedRegionConfigProviderName.GCP">GCP</a></code> | GCP. |
 | <code><a href="#awscdk-resources-mongodbatlas.AdvancedRegionConfigProviderName.AZURE">AZURE</a></code> | AZURE. |
 | <code><a href="#awscdk-resources-mongodbatlas.AdvancedRegionConfigProviderName.TENANT">TENANT</a></code> | TENANT. |
+| <code><a href="#awscdk-resources-mongodbatlas.AdvancedRegionConfigProviderName.FLEX">FLEX</a></code> | FLEX. |
 
 ---
 
@@ -48380,6 +48381,13 @@ TENANT.
 ---
 
 
+##### `FLEX` <a name="FLEX" id="awscdk-resources-mongodbatlas.AdvancedRegionConfigProviderName.FLEX"></a>
+
+FLEX.
+
+---
+
+
 ### ApiAtlasDiskBackupShardedClusterSnapshotMemberViewCloudProvider <a name="ApiAtlasDiskBackupShardedClusterSnapshotMemberViewCloudProvider" id="awscdk-resources-mongodbatlas.ApiAtlasDiskBackupShardedClusterSnapshotMemberViewCloudProvider"></a>
 
 Human-readable label that identifies the cloud provider that stores this snapshot.
diff --git a/TESTING.md b/TESTING.md
index b26e4d25..25e9b331 100644
--- a/TESTING.md
+++ b/TESTING.md
@@ -38,7 +38,7 @@ npx projen test
 
 ## Testing the resource in a CFN stack:
 1. Build the construct by running `npx projen build`.
-2. Navigate inside `/dist/js` and copy the`.tgz` file. You will use this in the next steps.
+2. It will generate a `.tgz` file in `dist/js` that we will reference later.
 3. Create a CDK test app: We will be using a CDK app to test our construct by using the app to create, update and delete AWS CloudFormation stacks.
 Create the CDK app by running the following in a terminal: ([refer AWS walkthrough for details](https://docs.aws.amazon.com/cdk/v2/guide/hello_world.html#hello_world_tutorial_create_app)):
 ```
@@ -48,10 +48,12 @@ cdk init app --language typescript
 # build the app:
 npm run build
 ```
-4. Copy the .tgz file from step #2 inside the node_modules folder in your CDK test app.
+4. Add a reference to the previous file in the `dependencies` section in `package.json` instead of using a published version, for example:
+```
+"awscdk-resources-mongodbatlas": "file:../dist/js/awscdk-resources-mongodbatlas@0.0.0.jsii.tgz"
+```
 5. Import your CDK construct in a testing project.
 6. Use the construct in your app with appropriate parameters.
- - [Optional, not applicable for L2/L3 constructs] If you need help getting test parameters to use with the constructs you can use `./cfn-resources/cfn-testing-helper.sh`. Refer “Getting test parameters” for creating a stack here for details.
 7. Build your app again.
 
 #### Create a stack:
@@ -79,4 +81,4 @@ cdk deploy
 2. Stack **Outputs** should show required data correctly.
 3. **Create** - Stack should complete successfully and resource should be created and correctly configured in Atlas account.
 4. **Update** - Stack should complete successfully and resource should be updated and correctly configured in Atlas account.
-5. **Delete** - Stack should complete successfully and resource should be deleted from your Atlas account.
\ No newline at end of file
+5. **Delete** - Stack should complete successfully and resource should be deleted from your Atlas account.
diff --git a/src/l1-resources/cluster/README.md b/src/l1-resources/cluster/README.md
index 71587149..4faf66bf 100644
--- a/src/l1-resources/cluster/README.md
+++ b/src/l1-resources/cluster/README.md
@@ -90,6 +90,25 @@ const clusterRes = new CfnCluster(this, 'ClusterResource', {
 
 ```
 
+You can also create a flex cluster using CfnCluster, for example:
+```ts
+import { CfnCluster, AdvancedRegionConfigProviderName } from 'awscdk-resources-mongodbatlas';
+
+const flexClusterRes = new CfnCluster(this, 'FlexClusterResource', {
+  name: atlasProps.clusterName,
+  projectId: projectRes.attrId,
+  profile: atlasProps.profile,
+  replicationSpecs: [{
+    advancedRegionConfigs: [{
+      regionName: atlasProps.region,
+      providerName: AdvancedRegionConfigProviderName.FLEX,
+      backingProviderName: "AWS",
+      priority: 7,
+    }]
+  }]
+});
+```
+
 ## Feedback
 
 This library is auto-generated and published to all supported programming languages by the [cdklabs/cdk-cloudformation] project based on the API schema published for `MongoDB::Atlas::Cluster`.
@@ -102,4 +121,4 @@ This library is auto-generated and published to all supported programming langua
 
 ## License
 
-Distributed under the Apache-2.0 License.
\ No newline at end of file
+Distributed under the Apache-2.0 License.
diff --git a/src/l1-resources/cluster/index.ts b/src/l1-resources/cluster/index.ts
index a9fc63e4..b22f807d 100644
--- a/src/l1-resources/cluster/index.ts
+++ b/src/l1-resources/cluster/index.ts
@@ -579,14 +579,14 @@ export interface Tag {
    *
    * @schema tag#Key
    */
-  readonly key?: string;
+  readonly key: string;
 
   /**
    * Variable that belongs to the set of the tag. For example, production in the environment : production tag.
    *
    * @schema tag#Value
    */
-  readonly value?: string;
+  readonly value: string;
 }
 
 /**
@@ -747,6 +747,8 @@ export enum AdvancedRegionConfigProviderName {
   AZURE = "AZURE",
   /** TENANT */
   TENANT = "TENANT",
+  /** FLEX */
+  FLEX = "FLEX",
 }
 
 /**